JPH079683Y2 - Vehicle heater performance improvement device - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a heater performance improving device for a large vehicle or the like, in which an exhaust brake is also used during idling to improve the heater performance.

[Prior art]

In large trucks used for long-distance transportation, drivers often take a nap in the car. Therefore, the heater performance to heat the inside of the vehicle at night or in cold weather such as winter is also an important selling point. Conventionally, the heater performance of a vehicle is improved by utilizing the cooling water temperature of the engine. However, if the engine performance is improved, combustion is good, and friction is reduced, the water temperature will not rise when idling. Therefore, the heater performance becomes insufficient in the cold season of winter. On the other hand, it is known that closing the exhaust brake valve during idling improves the heater performance. This is because the rise in exhaust pressure increases friction, the fuel injection amount increases, and the engine coolant temperature rises. However, if the exhaust brake valve is closed for a long time (for example, 6 hours) due to a nap or the like, there is a drawback in that the vibration of the engine becomes violent for the reasons described below and the comfort is greatly impaired. FIG. 3 shows an enlarged view of the exhaust brake valve portion. When the exhaust brake valve 2 and the inner wall of the exhaust duct 1 come into contact with each other when the exhaust brake valve 2 is closed, the return may be poor when the exhaust brake valve 2 is opened, or the bolt fixing the exhaust brake valve 2 may loosen. A time gap d is formed. However, if idling continues with the exhaust brake valve 2 closed, the exhaust brake valve 2 will be affected by the temperature of the exhaust gas.
Thermally expands, and this gap becomes smaller. Then, the exhaust resistance increases, the engine speed decreases, and the temperature of the exhaust gas rises. As the temperature of the exhaust gas rises, the gap becomes smaller. By repeating this, the engine speed gradually decreases, and eventually stable rotation becomes difficult, and the engine vibration becomes severe. When the number of rotations further decreases, it stops. FIG. 5 shows an operation characteristic diagram when the exhaust brake valve is closed for a long time in the conventional vehicle. FIG. 5 (A) shows a change in engine speed, FIG. 5 (B) shows a change in engine cooling water temperature, and FIG. 5 (C) shows a change in exhaust pressure. The jagged portion of FIG. 5 (a) shows a state where it is difficult for the engine to rotate stably. At this time, the vibration of the engine becomes severe. When the engine stops, the engine cooling water temperature
The exhaust pressure also gradually decreases. As a related document, the actual opening 57-168 in which the exhaust brake is controlled according to the engine cooling water temperature to promote warm-up
There is 742 publication.

[Problems to be solved by the device]

Although heating is performed in an idling state when a nap is taken in a vehicle, there has been a problem in the past that a comfortable heater performance could not be obtained for a long time. The present invention aims to solve such problems.

[Means for solving problems]

In order to solve the above problems, the present invention takes advantage of the temperature rise due to the closing of the exhaust brake valve and takes the following means in order to avoid unstable rotation of the engine due to long-term closing. That is, in the vehicle heater performance improving device of the present invention, the timer switch that is turned off intermittently is connected in series to the exhaust brake switch.

[Action]

When the exhaust brake valve is closed in the idling state, the engine temperature rises with the passage of time as described above.
However, the timer time is set so that the timer switch is turned off before the rotation of the engine becomes unstable. When the timer switch is turned off, the exhaust brake valve is opened. Then, the engine speed, which had been lowered, rises and stabilizes. After that, when the timer switch is turned on, the temperature rises again. By repeating these two states, the timer switch makes it possible to maintain a comfortable temperature state in the passenger compartment for a long time.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a heater performance improving device in a vehicle according to an embodiment of the present invention. In FIG. 1, 1 is an exhaust duct, 2 is an exhaust brake valve, 3 is a link mechanism, 4 is an air cylinder, 5 is an air pipe, 6 is a solenoid valve, 7 is an air tank, 8 is an accelerator switch, 9 is an exhaust brake switch, 10 is a battery and 11 is a timer switch. A feature of the present invention is that a timer switch 11 is connected in series with the exhaust brake switch 9. FIG. 2 is a diagram showing the operating characteristics of the timer switch used in the present invention. The time setting of the timer switch 11 is
A cycle of turning on for a time T ₀ (for example, 3 hours) and then turning off for a time T ₁ (for example, 30 seconds) is repeated. When the driver stops the vehicle and takes a nap, the engine is idling, and the accelerator switch 8 is turned on. Then, when the exhaust brake switch 9 is turned on, the solenoid valve 6 opens and air is supplied from the air tank 7 to the air cylinder 4. When the air cylinder 4 operates,
The exhaust brake valve 2 is closed via the link mechanism 3. FIG. 4 is a characteristic diagram when the heater performance improving device according to the present invention is operated. When the exhaust brake valve 2 is closed, the engine cooling water temperature and exhaust pressure rise as described above. On the other hand, the engine speed decreases. This state lasts for the time T ₀ during which the timer switch 11 is on. The length of the time T ₀ is set so that the engine speed will not drop too much and the rotation will become unstable and the vibration will become violent or stop. When the timer switch 11 is turned off, the exhaust brake valve 2
Is opened, the engine speed increases and the engine cooling water temperature and exhaust pressure decrease. Then, when the exhaust brake valve 2 is closed again, the previous state is restored. Since the above state is repeated by turning the timer switch 11 on and off, comfortable heating can be performed for a long time without destabilizing the rotation of the engine.

[Effect of device]

As described above, according to the present invention, even if the exhaust brake is closed and the temperature is raised in the idling state, the interior of the vehicle is kept in a comfortable temperature state for a long time without destabilizing the engine rotation. You can

[Brief description of drawings]

FIG. 1 ... Heater performance improving device for a vehicle according to an embodiment of the present invention FIG. 2 ... Diagram showing operation characteristics of a timer switch used in the present invention FIG. 3 ... Enlarged view of exhaust brake valve portion FIG. 4 ... Book Fig. 5 is an operating characteristic diagram of the invention. Fig. 5 is an operating characteristic diagram when the exhaust brake valve is closed for a long time in the conventional vehicle.
Is a link mechanism, 4 is an air cylinder, 5 is an air pipe, 6
Is a solenoid valve, 7 is an air tank, 8 is an accelerator switch, 9
Is an exhaust brake switch, 10 is a battery, and 11 is a timer switch.

Claims (1)

[Scope of utility model registration request] 1. A heater performance improving device in a vehicle, wherein a timer switch that is turned off intermittently is connected in series to an exhaust brake switch.